Microwave ablation system and user-controlled ablation size and method of use

ABSTRACT

Disclosed is a system and method for enabling user preview and control of the size and shape of an electromagnetic energy field used in a surgical procedure. The disclosed system includes a selectively activatable source of microwave surgical energy in the range of about 900 mHz to about 5 gHz in operable communication with a graphical user interface and a database. The database is populated with data corresponding to the various surgical probes, such as microwave ablation antenna probes, that may include a probe identifier, the probe diameter, operational frequency of the probe, ablation length of the probe, ablation diameter of the probe, a temporal coefficient, a shape metric, and the like. The probe data is graphically presented on the graphical user interface where the surgeon may interactively view and select an appropriate surgical probe. Three-dimensional views of the probe(s) may be presented allowing the surgeon to interactively rotate the displayed image.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation Application which claims the benefit of and priority to U.S. patent application Ser. No. 12/416,583 filed Apr. 1, 2009, now U.S. Pat. No. 9,277,969, the entire contents of which is incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to systems and methods for providing energy to biological tissue and, more particularly, to systems and methods for enabling user selection of the size and shape of a microwave energy field used in a surgical procedure.

2. Background of Related Art

Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency energy from the electrosurgical generator to the tissue and a return electrode carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated. A patient return electrode is placed remotely from the active electrode to carry the current back to the generator. In tissue ablation electrosurgery, the radio frequency energy may be delivered to targeted tissue by an antenna or probe.

In the case of tissue ablation, a high radio frequency energy in the range of about 300 mHz to about 300 gHz is applied to a targeted tissue site to create an ablation volume, which may have a particular size and shape. The particular type of tissue ablation procedure may dictate a particular ablation volume in order to achieve the desired surgical outcome. By way of example, and without limitation, a spinal ablation procedure may call for a longer, more narrow ablation volume, whereas in a prostate ablation procedure, a more spherical ablation volume may be required.

The ablation volume may be affected by various factors, including without limitation, probe construction, antenna size and shape, frequency, energy level, energy delivery method, and duration of energy delivery. Conventionally, a surgeon must rely upon professional experience and published specifications to select an ablation probe and related electrosurgical parameters with which to achieve a desired ablation volume for a particular patient.

SUMMARY

The present disclosure provides an electromagnetic surgical ablation system having a generator assembly that includes generator module that is configured to provide radiofrequency surgical energy, such as electrosurgical or microwave energy. A processor is included in the generator assembly that is operably coupled to the generator module and a user interface. The user interface may include a graphic touchscreen display, as well as switches and illuminated indicators. The user interface displays a graphical representation of a surgical instrument, such as without limitation a microwave antenna probe. The graphical representation includes an image corresponding to the instrument's radiating field, such as without limitation an antenna probe ablation pattern. The disclosed system includes a database in operable communication with the processor that is adapted to store probe parameters corresponding to at least one antenna probe. A user, typically a surgeon, may then use the user interface to graphically view various probe parameters stored within the database, and thereby choose an appropriate instrument (e.g., ablation probe) with which to perform a surgical procedure. In an embodiment, a shape selection user interface element is provided to receive a shape selection input, which may reflect the surgeon's choice of instrument. In an embodiment, an identifier within the selected probe is recognized by the generator assembly to confirm the actual probe used by the surgeon corresponds to the selected probe.

In some embodiments, a three-dimensional view of a probe and an ablation pattern corresponding thereto is displayed on the user interface. A rotation user interface element may be provided by the user interface, wherein rotation the user interface element is configured to accept an input which causes the user interface to rotate the displayed three dimensional view. In some embodiments, a temporal user interface element is provided by the user interface that is configured to accept a temporal user input which, in response thereto, causes the graphical display to present an animation representative of a change in a probe parameter with respect to time.

Also provided is a method for computer-assisted surgical instrument selection, comprised of providing a selectively-activatable source of electromagnetic surgical energy that includes a user interface, and providing a database in operable communication with the source of electromagnetic energy. The database is populated with at least one surgical instrument parameter and at least one identification parameter associated with a surgical instrument. A visual representation is generated of at least one instrument parameter and displayed on the user interface. At least one associated identification parameter associated with a surgical instrument (e.g., a model number or a clinical designation) may also be displayed. A surgeon responds to the visual display by selecting, with the user interface, a desired surgical instrument. The surgeon activates the source of electromagnetic surgical energy to supply electromagnetic surgical energy to the selected surgical instrument. A surgeon may view a plurality of probe images prior to making a selection.

Also disclosed is a computer-readable medium storing a set of programmable instructions configured for being executed by at least one processor for performing a method for computer-assisted surgical instrument selection as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a diagram of a microwave ablation system having a microwave antenna assembly in accordance with the present disclosure;

FIG. 2 shows a diagram of a microwave ablation system that includes a user interface for displaying and controlling ablation patterns in accordance with the present disclosure;

FIG. 3 is a block diagram of a microwave ablation system in accordance with the present disclosure;

FIG. 4A shows a user interface in accordance with the present disclosure wherein a side view of a first ablation pattern is displayed;

FIG. 4B shows a user interface in accordance with the present disclosure wherein a side view of a second ablation pattern is displayed;

FIG. 4C shows a user interface in accordance with the present disclosure wherein an oblique view of a second ablation pattern is displayed;

FIG. 4D shows a user interface in accordance with the present disclosure wherein an axial view of a second ablation pattern is displayed;

FIG. 5A is a graph in accordance with the present disclosure illustrating a relationship between an ablation diameter, time, and power with respect to a 12 gauge, 915 mHz choked wet tip dipole ablation probe;

FIG. 5B is a graph in accordance with the present disclosure illustrating a relationship between an ablation shape, time, and power with respect to a 12 gauge, 915 mHz choked wet tip dipole ablation probe;

FIG. 6A is a graph in accordance with the present disclosure illustrating a relationship between an ablation diameter, time, and power with respect to a 12 gauge, 2450 mHz choked wet tip dipole ablation probe;

FIG. 6B is a graph in accordance with the present disclosure illustrating a relationship between an ablation shape, time, and power with respect to a 12 gauge, 2450 mHz choked wet tip dipole ablation probe;

FIG. 7A is a graph in accordance with the present disclosure illustrating a relationship between an ablation diameter, time, and power with respect to a 14 gauge, 915 mHz choked wet tip dipole ablation probe;

FIG. 7B is a graph in accordance with the present disclosure illustrating a relationship between an ablation shape, time, and power with respect to a 14 gauge, 915 mHz choked wet tip dipole ablation probe;

FIG. 8A is a graph in accordance with the present disclosure illustrating a relationship between an ablation diameter, time, and power with respect to a 14 gauge, 2450 mHz choked wet tip dipole ablation probe; and

FIG. 8B is a graph in accordance with the present disclosure illustrating a relationship between an ablation shape, time, and power with respect to a 14 gauge, 2450 mHz choked wet tip dipole ablation probe.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.

In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, shall refer to the end of the instrument that is closer to the user, while the term “distal” shall refer to the end that is farther from the user.

FIG. 1 shows an embodiment of a microwave ablation system 100 in accordance with the present disclosure. The microwave ablation system 100 includes a microwave antenna probe 112 connected by a cable 115 to connector 116, which may further operably connect the antenna probe 112 to a generator assembly 200 configured to provide, e.g., microwave or RF energy in a range of about 915 mHz to about 2450 mHz. Antenna probe 112, as shown, is a dipole microwave antenna assembly, but other antenna assemblies, e.g., choked, wet-tip, monopole or leaky wave antenna assemblies, may also utilize the principles set forth herein.

In greater detail, FIG. 2 illustrates a microwave ablation system 100 in accordance with the present disclosure. The disclosed system includes an actuator 120, which may be a footswitch, a handswitch, a bite-activated switch, or any other suitable actuator. Actuator 120 is operably coupled by a cable 122 via connector 118 to generator assembly 200. Cable 122 may include one or more electrical conductors for conveying an actuation signal from actuator 120 to generator assembly 200. In an embodiment, actuator 120 is operably coupled to generator assembly 200 by a wireless link, such as without limitation, a radiofrequency or infrared link. At least one additional or alternative microwave antenna probe 112′ may be included with microwave ablation system 100 that may have characteristics distinct from that of microwave antenna probe 112. For example without limitation, microwave antenna probe 112 may be a 12 gauge probe suitable for use with energy of about 915 mHz, while microwave antenna probe 112′ may be a 14 gauge probe suitable for use with energy of about 915 mHz. Other probe variations are contemplated within the scope of the present disclosure, for example without limitation, a 12 gauge operable at 2450 mHz, and a 14 gauge operable at 2450 mHz. In use, the user, typically a surgeon, may interact with user interface 205 to preview operational characteristics of available probes 112, 112′ et seq., and to choose a probe for use in accordance with surgical requirements.

Generator assembly 200 includes a generator module 286 in operable communication with processor 282 that is configured as a source of RF and/or microwave energy. In an embodiment, generator module 286 is configured to provide energy of about 915 mHz. Generator module 286 may also be configured to provide energy of about 2450 mHz (2.45 gHz.) The present disclosure contemplates embodiments wherein generator module 286 is configure to generate a frequency other than about 915 mHz or about 2450 mHz, and embodiments wherein generator module is configured to generate variable frequency energy. Probe 112 is operably coupled to an energy output of generator module 286.

Actuator 120 is operably coupled to processor 282 via user interface 210. In embodiments, actuator 120 may be operably coupled to processor, and/or to generator 286 by a cable connection, or a wireless connection.

Generator assembly 200 also includes user interface 205, that may include a display 210 such as, without limitation, a flat panel graphic LCD display, adapted to visually display at least one user interface element 230, 240. In an embodiment, display 210 includes touchscreen capability (not explicitly shown), e.g., the ability to receive input from an object in physical contact with the display, such as without limitation a stylus or a user's fingertip, as will be familiar to the skilled practitioner. A user interface element 230, 240 may have a corresponding active region, such that, by touching the screen within the active region associated with the user interface element, an input associated with the user interface element is received by the user interface 205.

User interface 205 may additionally or alternatively include one or more controls 220, that may include without limitation a switch (e.g., pushbutton switch, toggle switch, slide switch) and/or a continuous actuator (e.g., rotary or linear potentiometer, rotary or linear encoder.) In an embodiment, a control 220 has a dedicated function, e.g., display contrast, power on/off, and the like. Control 220 may also have a function which may vary in accordance with an operational mode of the ablation system 100. A user interface element 230 may be positioned substantially adjacently to control 220 to indicate the function thereof. Control 220 may also include an indicator, such as an illuminated indicator (e.g., a single- or variably-colored LED indicator.)

Turning now to FIG. 3, generator assembly 200 includes a processor 282 that is operably coupled to user interface 210. A storage device 288 is operably coupled to processor 282, and may include random-access memory (RAM), read-only memory (ROM), and/or non-volatile memory (NV-RAM, Flash, and disc-based storage.) Storage device 288 may include a set of program instructions executable on processor 282 for executing a method for displaying and controlling ablation patterns in accordance with the present disclosure. Generator assembly 200 may include a data interface 290 that is configure to provide a communications link to an external device 291. In an embodiment, data interface 290 may be any of a USB interface, a memory card slot (e.g., SD slot), and/or a network interface (e.g., 100BaseT Ethernet interface or an 802.11 “WiFi” interface.) External device 291 may be any of a USB device (e.g., a memory stick), a memory card (e.g., an SD card), and/or a network-connected device (e.g., computer or server.) Generator assembly 200 may also include a database 284 that is configured to store and retrieve probe data, e.g., parameters associated with one or more probes 112. Parameters stored in database 284 in connection with a probe may include, but are not limited to, probe identifier, a probe diameter, a frequency, an ablation length, an ablation diameter, a temporal coefficient, a shape metric, and/or a frequency metric. In an embodiment, ablation pattern topology may be included in database 284, e.g., a wireframe model of a probe 112 and/or an ablation pattern associated therewith.

Database 284 may also be maintained at least in part by data provided by external device 291 via data interface 290. For example without limitation, probe data may be uploaded from an external device 291 to database 284 via data interface 290. Additionally or alternatively, probe data may be manipulated, e.g., added, modified, or deleted, in accordance with data and/or instructions stored on external device 291. In an embodiment, the set of probe data represented in database 284 is automatically synchronized with corresponding data contained in external device 291 in response to external device 291 being coupled (e.g., physical coupling and/or logical coupling) to data interface 290.

Processor 282 is programmed to enable a user, via user interface 205 and/or display 210, to view at least one ablation pattern and/or other probe data corresponding to a probe 112 et seq. For example, a surgeon may determine that a substantially spherical ablation pattern is necessary. The surgeon may activate a “select ablation shape” mode of operation for generator assembly 200, preview a number of probes by reviewing graphically and textually presented data on display 210, optionally or alternatively manipulate a graphic image by, for example, rotating the image, and to select an appropriate probe 112 et seq. based upon displayed parameters. The selected probe may then be coupled to generator assembly 200 for use therewith. In an embodiment, probe 112 may include an identifier (not explicitly shown) that provides an identification signal to generator assembly 200 to facilitate confirmation that a particular probe 112 of the selected type is coupled to generator assembly 200.

In an embodiment, a surgeon may input via user interface 205 a probe parameter to cause generator assembly 200 to present at least one probe corresponding thereto. For example, a surgeon may require a 3.0 cm diameter ablation pattern, and provide an input corresponding thereto. In response, the generator assembly 200 may preview a corresponding subset of available probes that match or correlate to the inputted parameter.

Turning now to FIGS. 4A-4D, generator assembly 200 provides a user interface 210 which may present a probe image 302. Probe image 302 may be a three dimensional (e.g., 3D) graphic rendering of the characteristics of probe 112 that are stored in database 284. Probe image 302 may be rendered using any suitable rendering technique, such as wire-frame projections and/or ray-tracing. User interface 210 provides a select ablation shape indicator 303, which may be a graphic icon or a textual command, that informs the user that generator assembly 200 is in a probe selection mode (e.g., probe select and/or ablation shape selection mode). A shape selection user interface element 305, 306 may be provided for receiving a shape selection user input thereby enabling a user to choose an ablation shape from among one of a set of ablation shapes and/or probes stored in database 282. A probe designation 301 (e.g., probe name) may be displayed. As seen in FIG. 4A, a shape selection user interface element 305, 306 may include a graphic icon, such as without limitation, an arrowhead, and/or may include textual commands, such as “previous” or “next.”

Additional parameters 307 of one or more displayed probes 112 may be presented on display 210, which may include probe diameter, frequency, ablation length, ablation diameter, and/or shape metric. A shape metric is defined as a minimum ablation diameter expressed as a percentage of a maximum ablation diameter, e.g., 100(d_(min)/d_(max)), where d_(min) is a minimum ablation diameter and d_(max) is a maximum ablation diameter.

By actuating a shape selection icon, a user may cause display 210 to depict characteristics of a different probe 112 as stored in database 282. For example, as shown in FIG. 4B, a user has made a shape selection by activating a shape selection user interface element 305, 306, causing an characteristics of an alternative probe 302′ to be displayed. The corresponding user interface elements are updated accordingly, such that, as seen in FIG. 4B, the corresponding probe designation 301′, probe image 302′; and additional parameters 307′ correctly reflect characteristics of the currently-displayed probe.

As shown in FIGS. 4C and 4D, the user may activate a rotate ablation image mode of display for generator assembly 200 wherein a rotation user interface element 312, 314 may be used to display alternate probe image views 302″, 302″′ in response to receiving a rotation user input. In an embodiment, rotation user interface element 312, 314 may be a hidden and/or invisible region of display 210, permitting the user to cause the probe image 302′ to be rotated by, for example, wiping a fingertip on the display 210 (e.g., gesturing) to indicate the direction and axis of rotation. Rotation user interface element 312, 314 may be visible and include arrowheads 311, 313, 315, 316 to denote upward rotation, downward rotation, left rotation, and right rotation, respectively, of probe image 302′.

In an embodiment, at least one patient image, e.g., ultrasound, CT scan, MRI, and the like, (not explicitly shown) may be presented on display 210 over which a displayed probe 302 is superimposed thereupon to enable the user to visualize an ablation pattern of a probe 302 in situ with surrounding tissue. The patient image may be a 3D image and responsive to an input received by rotation user interface element 312, 314, such that the patient image and displayed probe 302 rotate together in a substantially synchronized manner to enable a user to visualize the relationship of the probe 302, ablation pattern thereof and surrounding tissue from a plurality of viewing angles.

A temporal user interface element (not explicitly shown) may be provided to enable a user to view changes in an ablation pattern over time. Temporal user interface element may include, for example, a slider, which may be positioned at a desired point along a time scale to view an ablation pattern corresponding thereto. In an embodiment, actuation of a temporal user interface element may cause an animated depiction of an ablation pattern to be displayed. Such animation may be displayed in real-time, slower than real-time, or faster than real-time.

A user may confirm a probe choice by activating an accept selection user interface element 308, or exit a probe selection mode without making a selection by activating a cancel selection user interface element 309.

Turning now to FIGS. 5A, 5B, 6A, 6C, 7A, 7D, 8A, and 8B, examples of measures minimum ablation diameter and shape metric are shown with respect to probe diameter and operating frequency. FIG. 5A illustrates a relationship between an ablation diameter, time, and power of a 12 gauge diameter, 915 mHz choked wet tip dipole ablation probe. FIG. 5B is a graph illustrating a relationship between an ablation shape, time, and power of a 12 gauge, 915 mHz choked wet tip dipole ablation probe. FIG. 6A illustrates a relationship between an ablation diameter, time, and power of a 12 gauge diameter, 2450 mHz choked wet tip dipole ablation probe. FIG. 6B is a graph illustrating a relationship between an ablation shape, time, and power of a 12 gauge, 2450 mHz choked wet tip dipole ablation probe. FIG. 7A illustrates a relationship between an ablation diameter, time, and power with respect to a 14 gauge, 915 mHz choked wet tip dipole ablation probe. FIG. 7B is a graph illustrating a relationship between an ablation shape, time, and power with respect to a 14 gauge, 915 mHz choked wet tip dipole ablation probe. FIG. 8A depicts a relationship between an ablation diameter, time, and power with respect to a 14 gauge, 2450 mHz choked wet tip dipole ablation probe. FIG. 8B shows a relationship between an ablation shape, time, and power with respect to a 14 gauge, 2450 mHz choked wet tip dipole ablation probe.

While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

What is claimed is:
 1. A system for computer-assisted planning for a surgical ablation procedure, comprising: a processor; and a display operably coupled to the processor and controllable by the processor to display a user interface, the user interface including: at least one image based on patient image data; a shape selection user interface configured to receive a user input enabling a user to select an ablation shape from a plurality of ablation shapes stored in a database; at least one other ablation parameter related to the user selected ablation shape; a preview of selectable probes, wherein at least one of the selectable probes is a displayed probe which is configured to generate the user selected ablation shape; a rotation interface that rotates the at least one image, the user selected ablation shape, and the displayed probe in a synchronized manner in response to a user input; and a temporal interface that updates the user selected ablation shape over-time in response to a user input, the temporal interface including a slider element configured to be positioned at a desired point along a time scale to view the ablation shape corresponding to the desired point along the time scale.
 2. The system according to claim 1, wherein the patient image data is selected from the group consisting of x-rays, ultrasound, computed tomography (CT) scans, magnetic resonance imaging (MRI), and combinations thereof.
 3. The system according to claim 1, wherein the at least one other ablation parameter is selected from the group consisting of a probe diameter, a frequency, an ablation length, an ablation diameter, a temporal coefficient, a shape metric, a frequency metric, and combinations thereof.
 4. The system according to claim 1, wherein the user selected ablation shape is displayed over the at least one image.
 5. The system according to claim 1, wherein the user selected ablation shape is displayed as a three dimensional graphic rendering.
 6. The system according to claim 1, wherein the user selected ablation shape is displayed as part of a probe image.
 7. The system according to claim 1, wherein the at least one image is displayed as a three dimensional image and the selected ablation shape is superimposed over the at least one image. 